Structural-phase state and mechanical properties of submicrocrystalline titanium alloy Ti-6Al-4V obtained with use of reversible hydrogen alloying

Features of evolution of structural-phase state of titanium alloy Ti-6Al-4V at the process of submicrocrystalline structure formation using reversible hydrogen alloying have been investigated by methods of electron microscopic and X-ray diffraction analyses. Influence of hydrogen alloying on mechanical properties at stretching of submicrocrystalline titanium alloy Ti-6Al-4V in temperature interval of 293...1023 K was studied. Possible reasons of increase in ultimate and yield strength and reduction of deformation to destruction of submicrocrystalline alloy Ti-6Al-4V in temperature interval 873...1023 K at hydrogen alloying in quantity 0,08...0,33 mas. % were discusse

Dielectric response function PdHx system

The calculations of electron structure of pure Pd and PdHx (x=1,2,3) system have been made ab initio in the range of local density approximation. Total energy of PdHx system has been calculated for the cases of different coordination of hydrogen atom (oct-and tetrahedral), the conclusion on their most probable location in metal lattice has been made. In the approximation of constant matrix element the imaginary part of permittivity constant function ?2(?) has been calculated. It was stated that dissolution of hydrogen in palladium increases values of the function ?2(?) in the investigated range of energies from 2 to 24 eV. Therefore in the case of radiation impact on PdHx system one can expect intensive excitement of the crystal electron subsystem, and, hence, decrease of potential barriers for hydrogen atom movement

Influence of hydrogen on mechanical properties of [012]-crystals of austenitic steel Fe-18Cr-14Ni-2Mo

The influence of hydrogen alloying on critical shear stress, strain hardening coefficient and crystal plasticity depending on temperature of testing in the range of 77...400 К and hydrogen atom concentration has been investigated on monocrystals of austenitic stainless steel Fe-18Cr-14Ni-2Mo with low staking fault energy. Hydrogenation up to 14 at. % is shown to result in 1,5...2 increase of strength properties expressed by temperature dependence of critical shearing strains and to encourage development of local deformation by sliding

The investigation of hydrogen accumulation in zirconium alloy by thermostimulated gas evolution method

Thermostimulated gas evolution from zirconium alloy saturated by hydrogen E_125 versus deformation degree has been studied. Samples of zirconium were subjected to straining with relative lengthening 2,5; 5,0 and 10,0 %, then they were saturated with hydrogen by electrolyte method at current density 0,5 A/sm2 during 4 hours. Or vice versa, they were first saturated with hydrogen being subjected to deformation afterwards. The deformation of alloy samples results in trap formation with different energies of hydrogen bond. In this case both bond energy and hydrogen quantity caught in traps depends on both deformation size and succession of «deformation-saturation» actions. The values of hydrogen bond energies in traps are estimated. Types of traps are defined

Hydrogen effect on zirconium alloy surface treated by pulsed electron beam

Influence of modification by pulsed electron beam (PEB) and hydrogen adsorption in zirconium alloys have been investigated. Treatment of Zr–1Nb alloy by high-current PEB allows for a decrease in the amount of hydrogen absorbed by the samples during the hydrogenation process from gas atmosphere in the temperature range of (350–550 °С). The effect of the PEB surface treatment on the hydrogen adsorption connected with the formation of a protective oxide film after PEB irradiation and also by the formation of a specific hardening structure under the action of irradiation at temperatures exceeding the melting temperature from the subsequent high-speed surface cooling